Method of and apparatus for heating



Jan. 9, 1945. F. o. HEss METHOD 0F AND APPARATUS FOR HEATING Fi'led Jan. 20

ATTORNEY Patented Jan. 9, 1945 METHGD OF AND APPARATUS FOR HEATING Frederic 0. Hess, Philadelphia, Pa., assigner to Selas Corporation of America, a corporation of Pennsylvania Application January 20, 1940, Serial N0. 314,754

(Cl. S-27.4)

10 Claims.

My invention relates to the art of heating, and is concerned with an improvement for producing gaseous heat at extremely high temperatures for doing useful work. More particularly, the invention is concerned with producing gaseous heat at extremely high temperatures with the aid of an improved torch burner having refractory material embodied therein.

It is an object of the present invention -to provide an improved torch burner for producing gaseous heat which may be used, for example, for metal cutting, glass polishing, lead burning and analogous operations in which the desired heating is effected by directing a jet of very hot gas against the work operated on. More specifically, it is an object to provide a torch burner adapted to burn a combustible mixture of air and gas, and thereby develop jet temperatures high enough for torch burner uses whichheretofore have required the use of oxygen as a combustion supporting agent. y

A further and still more specific object of the invention is to provide a torch burner comprising a refractory walled combustion chamber into which a combustible mixture is introduced in a plurality of small gas streams and in which combustion of the combustible mixture is effected substantially completely in such manner as to maintain a very high combustion chamber temperature, and to highly heat the combustible mixture burned in the chamber.

In the preferred form of the invention, all of the fuel used, is supplied .directly to, and burned in the refractory walled combustion chamber, in which complete or practically complete combustion is theneffected, and from which the burned gases issue through a restricted discharge nozzle or jet outlet in a suitably shaped jet at a suitably high velocity and at a temperature which ordinarily is about 3000 F. or higher.

Another specific object of the invention is to provide a torch burner having the cross sectional area of the small inlet openings or ports, through which combustible mixture is passed into the refractory walled combustion chamber of the burner, in subdivided streams, of such size relative to the area of the restricted outlet port through which products of combustion are discharged from said chamber, that the pressure in the chamber will be substantially higher than the pressure of the atmosphere into which the burner torch jet 'is discharged from the combustion chamber. The maintenance of such high combustion chamber pressures contributes to the attainment of high combustion chamber temperatures and to high burner combustion capacities.

My improved torch burner in all of its forms, is characterized by an extraordinarily high combustion capacity. For example, it has been found possible in the use of my torch burner to burn a combustible mixture of air and gas at the rate required to liberate about fourteen million B. t. u.s per cubic foot of combustion chamber space per hour, whereas, heretofore, the liberation of four million B; t. u.s per cubic foot of combustion chamber space per hour has been regarded as about a practical maximum.

The various features of novelty which characterize my invention are pointed out with particularity in the claims. The invention, both as to organization and method, together With'the objects and advantages thereof, will be better understood by reference to the following description taken in connection with the accompanying drawing forming a part of this specification, and of which:

Fig. 1 is a sectional elevation, and Fig. 2 is an end view of one form of my improved torch burner;

Fig. 3 is a sectional elevation, and Fig. 4 is an end view of a second form of the invention;v

Fig. 5 is a sectional elevation, and Fig. 6 is an end view of a third form of the invention; and

Fig. 7 is a sectional elevation, and Fig. 8 is an end View of a burner including special provisions for preventing burner heat radiation losses and increasing the burner jet temperature.

Referring to Figs. 1 and 2 illustrating an embodiment of the invention, a burner B includes an outer metallic shell bc which is formed with inwardly extending ilanges I0 at one end and internally threaded at its other end to receive a base member AC. Within the shell be is disposed a hollow body of refractory material comprising two sections BC and BC' formed to provide a refractory lined combustion chamber CC. The sections BC and BC are held in the shell bc between the flanges IIJ and base member AC, and the top section BC is formed with a central raised portion B02 in which is provided a slot C5 serving as a restricted outlet or discharge oriiice.

The base member is formed with an inlet open` ing I l which is adapted to be connected to a suitable source of supply of a gaseous fuel mixture. The inlet opening i I communicates with a chamber A' in base member AC which is internally threaded to receive an externally threaded orifice member DC formed of refractory material. The bottom end of the orifice member is tapered, so

. that the gaseous fuel mixture introduced into the chamber A is distributed into a plurality of streams passing through slots or channels D5 formed about the periphery of and extending lengthwise of the intermediate part and underside of the enlarged upper end of the orifice member DC. The upper ends of the channels D5 at the underside of the enlarged inner end of the orifice fnember DC are outwardly toward theinner refractory lining I2 of the combustion chamber CC.

In the intended operation of the burner B, a suitable gaseous fuel mixture is supplied under pressure to the inlet II from a source of supply. 'Ihe fuel mixture is distributed by the tapered lower end of orice member DC about the periphery of the latter and flows through the channels or slots D5. The fuel mixture is discharged from the outlet ends of the channels at the underside of the enlarged upper end of the orifice member DC, and at these regions the burner flames are produced and maintained. The individual flames produced at the outlet ends I4 of the channels ,D5 flare outwardly and project into the combustion chamber CC alongside of the outwardly fiaring bottom portion of the inner lining I2. After an interval of time the flames maintained in the combustion chamber CC effect such heating of the inner lining I2 that the latter is heated to a high incandescent temperature.

Due to heating the inner refractory lining I2 to a high incandescent temperature, and subjecting the gaseous mixture entering the combustion chamber CC to intense heat radiated from the highly heated incandescent lining I2, substantially complete combustion of the gas mixture may be effected in the combustion chamber CC before the gas mixture reaches the restricted outlet C5. From the restricted outlet C5 is discharged a high velocity jet or stream of heated gases consisting substantially entirely of the heated products of combustion.

The burner shown in Figs. 1 and 2 is provided with a discharge orifice C5 which is relatively wide and narrow and of slot-like form. In many applications it may be desirable to provide burners having discharge orifices of varying shape to effect heating of work expeditiously. Thus, in Figs. 3 and 4 is illustrated a burner B which is generally similar to that shown in Figs. 1 and 2 and differs therefrom in that the restricted outlet C5 is round.

In theA burner B' the base member AD is provided with lugs A5 to which one end of the shell bd is secured by screws bd. The combustion chamber CD is formed by a hollow refractory body comprising two sections BD and BD' held in the shell bd between the inwardly extending flange Illa and the base member AD. The orifice member DC is similar to that in Fig. l with individual streams of the gaseous fuel mixture adapted to flow through the slots or channels D5 in the same manner described above in connection with the burner B illustrated in Fig. 1.

In the burner shown in Figs. 3 and 4, the inner lining I2a is heated to incandescence by the flames produced at the slot outlets I4a and the radiant heat from the highly incandescent inner lining forms a region of intense heat, so that substantially complete combustion of the gaseous fuel mixture may be effected in the combustion chamber. The heated products of combustion are discharged from the restricted outlet C6, and such heated gases can be utilized to do useful work at extremely high temperatures corresponding or'nearly equal to the temperature developed and maintained in the combustion chamber CD.

The burner B2 shown in Figs. 5 and 6 illustrates another embodiment for carrying out the present invention in which the blast of heated gases issuing from the restricted outlet C" is utilized to produce useful work for so-called fire polishing the mouths of bottles, such as, for example, milk bottles and the like. The burner B2 is generally similar to that illustrated in Figs. 3 and 4, and

* similar parts are designated by the same reference characters and numerals. In Figs. 5 and 6 a refractory body F of circular shape is mounted upon and secured to the orifice member DD. The bottom section BD of the refractory body is similar to the corresponding part in Fig. 1, but the section BD2 is formed to provide the annular or ring-shaped outlet C".

'I'he blast of heated gases discharged from the outlet C" can be effectively utilized for fire polishing the mouth X of a bottle, as shown in Fig. 5. The blast of heated gases melts a thin surface layer of glass at the extreme end of the bottle to provide a smooth surface not produced when the bottle is formed in the ordinary bottle molding machine. The refractory body F and the section BD2 of the refractory body form an outlet of definite shape, so that the heated gases will not impinge against the internal shoulder X' which is formed within the mouth X and serves as a seat for the usual paper bottle cap.

In each of the embodiments described above, the body of highly refractory material possesses such thermal properties that a poor thermal conductive path is provided through the refractory wall whereby the heat loss therethrough is kept at a minimum. However, in order further to reduce loss of heat through the inner refractory.

wall and effect higher combustion chamber temperatures, the gaseous fuel mixture may be delivered to the burner inlet through a closed chamber enveloping the burner proper. Such an arrangement is shown in Figs. 7 and 8 in which the burner B5 includes a base member A having a chamber A' into which the gaseous fuel mixture lenters through a plurality of openings or ports To the base member A is threadedly secured an annular part I5 which threadedly receives an end of a ring-shaped metallic shell b. Within the shell b is disposed a hollow refractory body BD3 which is recessed at its top edge to receive an inwardly extending flange I6 at the upper end of the shell b. The hollow refractory body 13D3 forms a combustion chamber C at the upper end of which is formed a restricted outlet or discharge orifice C. Adjacent to the chamber A is positioned an orifice member DE having a shoulder I'I which is held in position at an undercut or recessed portion of the annular part I 5. The orince member DE is provided with a plurality of small parallel passages or openings DE to effect distribution of the gaseous fuel mixture introduced into the combustion chamber C.

About the shell b, part I5, and base member A is provided a jacket G forming a space g enveloping the parts just described. The upper part of jacket G is formed with an inlet opening G to which the gaseous fuelmixture is supplied under pressure from a suitable source of supply. 'I'he inlet G is so positioned with respect to the inlet ports A5 that the space g provides a path of fiow for the gaseous fuel mixture which envelcps the shell b and inlet chamber A. The fuel mixture enters the chamber A' through the ports A6 and passes therefrom through the openings DE' in the orifice member DE into the combustion chamber C.

During normal operation of the burner B3, the burner flames are producedand maintained at the upper ends of the openings DE'. Substantially complete combustion of the gaseous fuel mixture is accomplished in the combustion chamber C in the same manner as in the embodiments previously described. and the heated products of combustion are discharged through the restricted outlet C' at an extremely high temperature and at a relatively high velocity. By providing the jacket G and utilizing the space g as a path of ow for the gaseous fuel mixture prior to entering the chamber A', the dissipation of heat from the shell b is reduced whereby higher combustion chamber temperatures may be obtained.

All of the burner forms illustrated are generically alike, in that each comprises a combustion chamber enclosed by a wall of refractory, nonmetallic material and having a restricted outlet orifice and an inlet formed with a number of small passages -for a combustible fluid mixture supplied under pressure, which is in communication with said chamber for the passage of the mixture into said chamber for combustion therein, and which is in communication with said orifice for the flow of fluid from said inlet along a path of flow heated by said combustion in said combustion chamber to said outlet orice and its discharge through the latter, in the form of a high velocity, high temperature jet. Because of the high temperature and high velocity character of the jet which it discharges, each of the burner forms shown is practically capable of operative effects not heretofore obtainable with torches not making use of oxygen as a combustion supporting agent.

Thus, in each of the burners shown, all of the combustible mixture supplied to the inlet of the burner is passed directly into the combustion chamber of the burner for practically complete combustion therein, and all of the fluid discharged from the combustion chamber, is included in and forms part of the high velocity jet, delivered by the burner.

With burners of the general type shown in Figs. l to 8, relatively high jet velocities and temperatures are obtainable by making the outlet port area of the burner combustion chamber not more than four times the aggregate port area through which the combustible mixture is supplied to the combustion chamber, and in some such burners in commercial use, the ratio of the outlet port area to the inlet port area is considerably smaller. Thus, for example, in one commercial form of my improved torch burner, having a combustion chamber oblong in cross section with a narrow elongated outlet port, like the port C of Figs. 1 and 2, which is approximately :A of an inch long, and which is about :im of an inch wide, the combustible mixture is supplied to the vcombustion chamber through fourteen orifices like the orifices DE in the member DE of Fig. 7 each of a diam- In the burners of the last mentioned type and form, the pressure at which the combustible mixture is supplied to the burner orifices D5 may Well vary from a pressure of 1/2 inch, to a pressure of 1% inches of mercury, and the corresponding combustion chamber pressures will then vary from a pressure of A inch, to a pressure of 1 inch of mercury above that of atmospheric which is equivalent to a pressure greater than 10 inches of water column. As will be apparent to those skilled in the art, with combustion chamber temperatures of 3000" or higher, the volume of the products of combustion discharged from the cornbustion chamber is several times the volume of the combustible fuel mixture which is supplied to the' combustion chamber at atmospheric temperature, or, in any event, at a temperature very much lower than the combustion chamber temperature. A high temperature torch jet is ordinarily highly important, since the heating effect is a function of the difference between the temperature at which the torch jet impinges against the work surface and the temperature of that surface, and that surface will ordinarily heat up very rapidly. The high combustion temperatures and pressures, which are characteristic of my invention, contribute to the efcient and rapid combustion of a combustible mixture including no excess air and thereby contribute to high torch jet temperatures, and correspondingly high differentials between the .iet a'nd work temperatures.

In view of the foregoing, it Will now be apparent that an improvement has been provided for producing gaseous heat at an elevated temperature for doing useful work; and that when a combustible mixture of air and city gas, having a rating of about 500 B. t. u. per cubic foot, is employed, it is kpossible to developwjet temperatures of 3000 F. or higher. In Figs. 7 and 8 the orice member DE may be a molded body of suitable material having the small inlet passages DE formed therein. In order to withstand the high eter of about .0465 inch. .In other commercial temperatures produced, the refractory walls of the combustion chambers and orifice members are preferably formed of lhighly refractory material. For example, the refractory body disposed within the outer shell of the burner may be formed or consist largely of magnesia oxide, and the orifice members or small passages at the inlet may be formed of beryllium oxide.

In each of the burners described and illustrated, the inner refractory wall surface of the hollow refractory body not only forms the inner lining for the combustion chamber but also forms or defines the restricted outlet or discharge orice. Further, in each of the embodiments the substantially closed combustion chamber and inlet and outlet are so formed that extremely high combustion chamber temperatures may be produced and maintained. It is for this reason that the inlets are formed with a multiplicity of small passages each of which is much smaller in section than the cross sectional area of the combustion chamber. Further, the combustion chamber may be formed so that its cross sectional area is greater in its middle or intermediate portion than adjacent to the inlet and outlet, as shown in the burners of Figs. 1 to 6 inclusive. To bring about eicient heating of the incandescent lining, the axes of all or a portion of the small inlet passages are out of line with the axis of the restricted outlet.

By confining the combustion or burning of the gaseous mixture within the combustion chambers which are substantially closed and provided with restricted outlets like those shown, the combustion chambers may be maintained at a pressure substantially above that of atmospheric during normal burner operation, as explained above. In the burners illustrated the cross sectional area of the restricted outlet is not more than onefourth of that of the chamberin order to develop such back pressure that the combustion chamber may be maintained substantially above atmospheric pressure during normal burner operation.

In the foregoing description the burners have been referred to as torch burners and the hot gases discharged therefrom as J'ets. Since the burners illustrated and described are of a type in which the jets are high velocity gas streams for heating and doing useful work and may be of different shapes, the term jet in the description and claims should be interpreted to include a high velocity gas stream of annular or circular or elongated cross section.

The torch burners illustrated and described herein are heating torches as distinguished from illuminating torches and accordingly in the claims the expression torch burner should be interpreted as a type of gas burner in which the hot gases discharged therefrom are of the character for heating o-r doing useful work as distinguished from a burner for producing light.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that variations and changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of my invention, as set forth in the following claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A torch burner for producing high temperature heat comprising structure providing a substantially closed combustion chamber having an inlet and a restricted outlet, said inlet having a plurality of openings for subdividing into a plu rality of gas streams a gas mixture adapted to be supplied thereto and consisting of a combustible gas and a combustion lsupporting gas, said combustion chamber having its restricted outlet and inner wall surface formed substantially entirely of high temperature refractory material, the gas mixture adapted to be supplied at said inlet into said combustion chamber being ignitible therein to burn the gas mixture to thereby heat said inner refractory wall surface to a high temperature, said combustion chamber thereby forming a confining space in which burning of the gas mixture is confined to provide a region of intense heating and in which substantially complete burning of the combustible mixture is effected, so that heated products of combustion are discharged from said outlet in the form of a gas stream at a temperature substantially corresponding to the temperature in said combustion chamber.

2. A gas burner for producing high temperature heat, said burner comprising a body having a cavity provided with a high temperature inner refractory wall surface forming a combustion chamber having an inlet for gaseous combustible mixture and an opening formed substantially entirely of said high temperature refractory material through which heated products` of combustion are discharged, a member of high temperature refractory material mounted in said combustion chamber and cooperating with said opening to provide an annular-shaped restricted outlet for the products of combustion and substantially closing said chamber, said chamber forming a space in which combustion of the combustible mixture is confined to provide a region of intense heating and in which substantially complete combustion of the gaseous mixture is effected, so that the products of combustion are discharged from the annular-shaped outlet at a temperature substantially corresponding to the temperature in said chamber.

3. A gas burner comprising structure having a cavity provided with a high temperature inner refractory wall surface forming a substantially closed combustion chamber having an inlet for a mixture of a combustible gas and a combustion supporting gas and a restricted outlet for products of combustion formed substantially entirely by said refractory wall surface, said combustion chamber forming a space in which combustion of said mixture is confined to provide a region of intense heating and in which substantially complete combustion of said mixture is effected, so that the products of combustion are discharged from said outlet at a temperature substantially corresponding to the temperature in said chamber, a jacket disposed about saidstructure and providing a space about the latter, said space being in communication with said inlet at a first region and having an opening `at a second region removed from said first region adapted to be connected to the source of supply of said mixture,-

" bustion discharged in the form of a gas stream at a temperature substantially corresponding to the temperature in said chamber.

5. A torch burner comprising structure providing a substantially closed combustion chamber having a restricted outlet and an inlet to which is adapted to be supplied under pressure a gas mixture consisting of a combustible gas and a combustion supporting gas, said inlet having a number of small passages each of which is much smaller in section than the cross sectional area of said chamber, so that the gas mixture adapted to be supplied to the inlet is subdivided into a plurality of small gas streams issuing into said chamber from said passages, and said chamber having its restricted outlet and inner lining formed substantially entirely of high temperature refractory material so that combustion of the small gas streams may be effected within said chamber to cause heating of said lining to incandescence and produce a region of intense heat in which substantially complete combustion is effected while a stream of products of combustion is discharged from the chamber through the restricted outlet at a temperature nearly equal to the temperature maintained in said combustion chamber.

6. A torch burner comprising structure providing a substantially closed combustion chamber having a restricted outlet and an inlet to which is adapted to be supplied under pressure a gas mixture consisting of a combustible gas and a combustion supporting gas, said inlet having two or more passages whose axes are out of line with the axis of the outlet so that the gas mixture adapted to be supplied to the inlet is subdivided into a plurality of gas streams issuing into said chamber from the passages, and said chamber having its restricted outlet and inner lining formed substantially entirely of high temperature refractory material so that combustion of the gas streams may be effected within said chamber to cause heating of said lining to incandescence and produce a region of intense heat in which substantially complete combustion is effected while a stream of products of combustion is discharged from the chamber through the restricted outlet at a temperature nearly equal to the temperature maintained in said combustion chamber.

7. .A torch burner comprising structure providing an inlet and a restricted outlet and between them a closed combustion chamber whose cross sectional area is greater in its middle portion than adjacent to the outlet and inlet, said inlet having a number of passages for subdividing into a plurality of gas streams a gas mixture adapted to be supplied thereto under pressure and consisting of a combustible gas and a combustion supporting gas, and said chamber having its restricted outlet and inner lining f ormed substantially entirely of high temperature refractory material so that combustion of the gas streams may be effected within said chamber to cause heating of said lining to incandescence and produce a region of intense heat in which substantially complete combustion is eiected while a stream of products of combustion is discharged from the chamber through the restricted outlet at a temperature nearly equal to the temperature maintained in said combustion chamber.

8. A torch burner comprising a hollow body which provides a substantially closed combustion chamber, an inlet and a restricted outlet whose cross sectional area is not more than one-fourth of that of said chamber, said inlet having a number of passages .for subdividing into a plurality of gas streams a. gas mixture adapted to 'be supplied thereto under pressure and consisting of a combustible gas and a combustion supporting gas, and said chamber having its restricted outlet and inner lining formed'substantially entirely of high temperature refractory material so that combustion of the gas streams may be effected Within said chamber to cause heating of said lining to incandescence and produce a region of intense heat in which substantially complete combustion is effected while a stream of products of combustion is discharged from the chamber through the restricted outlet at a temperature nearly equal to the temperature maintained in said combustion chamber.

9. In the art of heating work by a, high temperature gas stream prepared with the aid of a substantially closed combustion chamber having an inner surface and a restricted outlet formed substantially entirely of high temperature refractory material and an inlet having a multiplicity of passages, the improvement which includes supplying a combustible gaseous mixture under pressure through the passages into said chamber for combustion therein, igniting said mixture while within said chamber, thereby heating said inner surface, the resulting radiant heat from said inner surface acting to effect substantially complete combustion Within the chamber, discharging the products of combustion from said chamber through said outlet in the form of a jet, and directing said^jet against the work. to be heated.

10. In the art of heating work by a high temperature gas streamprepared with the aid of a substantially closed combustion chamber having an inner surface and a restricted outlet formed substantially entirely of high temperature refractory material and an inlet having a multiplicity of passages, the improvement which includes supplying a mixture of air and gas under pressure through the passages into said chamber for combustion therein, igniting said mixture while within said chamber, thereby heating said inner surface, the resulting radiant heat from said inner surface acting to effect substantially complete combustion within the chamber at a pressure of at least ten inches of water in excess of the back pressure at the discharge end of the outlet to cause liberation of heat at a rate above 4,000,000 B. t. u. per hour per cubic foot of combustion chamber space, discharging the products -of combustion from said chamber through said FREDERIC O. HESS. 

